BRRA is a exhaust air cowl with variable exhaust, which means the exhaust rate can be adjusted to current airflow. The air cowl has a design that allows the extracted air to rise straight up at an increased speed and is equipped with internal water deflector which mitigates water ingress when the extractor fan is not in operation.
BRRA is available in two variants, manual or automatic switchable. Several systems are constructed today without knowing what activities/tenant will use the facilities. The exact airflows can therefore not be determined during the planning stage and thus attempts are made to build flexibility into the facility. BRRA manual regulation (type 1) is designed to easily switch between different airflow rates. In systems with variable airflows, e.g. laboratories, hospi-tals and industries the entire ventilation system is built to regulate based on the current airflow requirements and it may differ significantly between the minimum and maxi-mum flow. BRRA automatic control (type 2) maintains the outlet speed constant with motor control. It means that you have control of the extract air and reduces the risk of shock-circuiting or impact.